微咸水膜下滴灌对土壤盐分及棉花产量的影响

合理利用微咸水资源灌溉对于缓解新疆南部地区淡水资源短缺的问题有着至关重要的意义。本文以库尔勒31团棉田为供试对象,淡水作为对照,利用排碱渠咸水与淡水不同比例混合,设置6种梯度配比,研究微咸水及咸水对棉田土壤盐分分布及产量的影响。结果表明:①随着矿化度的增加,各处理土壤盐分呈现不同程度的增加,其中处理5(全咸)增加程度最大,积盐率为131.03%。②在垂直方向上,随着土层深度的增加,各处理土壤盐分在20~40 cm处达到峰值;在水平方向上,盐分累积程度的大小为:膜间>宽行>窄行。③随着矿化度的增加,棉花的产量逐渐下降,棉花产量下降的主要因素是单株结铃数,而单铃重对棉花产量无明显影响。由膜下滴灌土壤盐分对棉花生长和产量的影响得出,当灌溉水的矿化度在淡咸水比为4∶1(矿化度2.36~3.39 g·L^-1)时对棉花生长的抑制作用较小,较对照处理相比,产量减少11.85%。

Effects of drip irrigation under a brackish water film with respect to the soil salinity and cotton yield

Water scarcity is a major factor that affects the sustainable development of agriculture in Xinjiang.However,brackish water contains abundant natural resources in Xinjiang,and reasonable utilization of brackish water in agriculture is of considerable significance to cope with the water scarcity problems,increase the crop yield,and conserve freshwater resources in southern Xinjiang.The objective of this study is to investigate the effects of the utilization of brackish water exhibiting different degrees of mineralization on the soil salt distribution,yield components,and seed cotton yield.A field experiment was conducted at the 31 st Regiment of Yuli County in Korla City,Xinjiang Province,Northwest China.Six different volume ratios of freshwater to saltwater,freshwater (CK),4∶1 (treatment 1),3∶2 (treatment 2),2∶3 (treatment 3),1∶4 (treatment 4),and saltwater (treatment 5) were verified via a field experiment.The results indicate that the soil salinity significantly increased for treatments 1-5 when compared with CK.The highest soil salinity was obtained using treatment 5,where the relative growth rate of the soil salinity reached 131.03%.In the vertical direction,the soil salinity initially increased and subsequently decreased with increasing soil depth;the soil salinity under all the treatments is observed to primarily accumulate in the 20-40 cm soil layer.In the horizontal direction,the order of soil salinity at different locations was no-mulch zone >wide row > narrow row.In addition,the boll numbers per plant significantly decreased with increasing mineralization degree.However,there were no significant differences in the weight per boll for different treatments.The seed cotton yield significantly decreased with increasing mineralization degree.Compared with CK,the seed cotton yield decreased by 11.85%,22.37%,28.66%,37.78%,and 59.69% in treatments 1-5,respectively.The reduction in the seed cotton yield under treatment 1 was minimal.This study suggests that the optimal volume ratio of freshwater to saltwater is treatment 1 (4∶1).Accordingly,the usage of treatment 1 (4∶1) is recommended to deal with water scarcity and ensure sustainable agricultural development in southern Xinjiang.